I shall now proceed to review the improvements which have been patented during the current year in the above classes, under their appropri"ate subdivisions, commencing with of . . . . . . . . . . . . . , - a --- * * * * METALLURGY AND MANUFACTURES IN METALS.

This class has many subdivisions, as may be inferred from the fact that

it comprehends the various modes of obtaining the different metals from

the ores, &c., together with the multifarious modes of preparing and applying them to use in the arts. The subdivisions will be presented in their order. The importance of improvements in this class cannot be overrated. The use of one of the metals—iron—exerts a controlling influence over the condition and advancement of society. No nation ever emerged from

"barbarism without its use; and it is not claiming too much for it to say

that civilization would not long exist without it. Improvements in manufactures of iron have always kept pace with, and presents the surest index to, the progress of man. . . In some branches of metallurgy inventions have been numerous, while others present but few improvements. Gold.—But one patent has been granted for separating gold from its

"impurities. It is an operation involving but little difficulty, and that of a "simple mechanical character, and therefore improvements are but rarely to

be expected. The following extract from the patent will fully explain the character of the invention : “By the ordinary and common processes of the separation of gold and 'silver from their ores, by washing with water and amalgamation, with mercury, there has always been a loss of both gold and silver, as well as of "the mercury. In the hand rocker and semi-circular, though usually worked by ind the quantity of sand and gravel which these machines can work is small; consequently, when that contains but little gold or platinum it cannot be worked with profit; and in these machines there is a "great loss of both gold and platinum, as well as quicksilver, (when that is used,) because the motion is half the time in one direction and half the time in another, by which the gold, &c., is prevented from subsiding, and consequently passes off with the water and sand. In the Binke rocker there is yet a greater waste of quicksilver and the precious metals. In the Tyrolese bowls the sand and gravel subside too soon to the bottom, and prevent the contact of the gold and silver with the quicksilver. My machine, I believe, will obviate all these practical evils, which heretofore have attended the extraction of the precious metals from the ores and earthy or stony mixtures. These objects I effect in the way and manner following: - * “I form a frame of wood, or any suitable material of convenient proportions; near each end of this frame there is a vertical, shaft; these shafts have each two sunk cranks, and formed on them at right angles to each other, and at equal heights on both shafts to the lower cranks, an oblong rectangular horizontal frame is coupled, so as to partake of and describe circles in each and every part of the frame, equal to the circles described by the cranks when they are moved. To the cranks above there is a con“necting rod which serves to secure the proper rotation of the lower cranks and frame in the same direction. The whole may be put in motion by any convenient, and proper motive power, transmitted through the intervention of an additional shaft, also vertical, and consequently parallel with those above described, the velocity being regulated by cones, connected by a band which is moved up and down at the will of an attendant, by a lever or other contrivance, a device well known to mechanics. A band on the additional pulley connects it with the prime mover. The frame is kept in a horizontal position by means of chains, or any other convenient mode of suspension, attached to its corners and extending up to the stationary frame above. By thus suspending the frame it is evident that, however much weight may be placed upon it, the cranks will not support it, and thus leave them at liberty to convert all their received so into rotary motion without much friction. On this frame are placed any convenient number of pans of circular form, with flat bottoms, or with bottoms grooved in concentric rings. To the bottoms of these pans are affixed . . four (more or less) legs, which fit into holes let into the frame to receive . . them. The legs on one side of the pans are made longer than those on . the other, so that the side which has the longer legs can be elevated by inserting a block between it and the frame, to enable the operatives to cleanse the pans speedily. The longer legs are opposite the gate; so that when the sides of the pans are elevated, the amalgam, &c., will be readily taken out. In each pan a gate or sliding piece is fitted, which can be made to slide down or up, so as to permit the water, sand, &c., to escape. “By the above description it will be seen that the motion effected by my machine in the pans is |...} similar to that of a person panning by hand ; which motion, all who are iii the least acquainted with the opera. tion of extracting gold, &c., know to be the only one which will save all the precious metals.” s o “In using this machine for extracting gold, silver, and platinum, it is necessary that the metals be disengaged from their matrix, and free to obey the law of gravity; therefore, ores that contain gold and silver must be ground to powder, so that these metals may be free to descend by their weight to the bottom of the pans.” Iron.—But few improvements have been patented for improvements in the manufacture of iron and steel; but some of those have been regarded as presenting great advantages. The problem of obtaining pure malleable . iron directly from the ore is still in progress of solution. Of the numerous processes heretofore resorted to, none seem to give entire satisfaction, or command general confidence. The following extract from a patent this year presents a process possessing novelty and plausibility; but it is impossible, for reasons set forth in my last report, to determine a priori what will be the practical results of any process, however well digested. Experience alone is the proper test; and even when perfectly successful with one kind of ore, the process may wholly fail when applied to another. . How far the following process may have succeeded 1 am not fully informed; but its friends have appeared full of confidence in its merits: “My improved process is applicable to the treatment of oxides of iron only; and this I effect in reverberatory furnaces, although some parts of . , the process may be applied in furnaces without the reverberatory feature. . . “It has long been essayed to reduce the oxides of iron directly into the metallic state by heating the ores mixed with carbonaceous matter, with . the view to produce deoxidation, and then to transfer the mass thus, treated to the puddling process; but in all these, which have so far been

unsuccessful, the upper stratum only of the mass of ore and carbon was"

exposed to the direct action of the heat and flame, instead of the whole mass; and to avoid this evil, it has been suggested to apply heat to the mass of ore and carbon below as well as above, by placing the fire grate directly under the furnace hearth or floor, and then reverberating the flame'and passing it over the charge. This modification, while it removes the leading objection of the process above indicated, introduces practical difficulties of such magnitude as to defeat the contemplated object. “My improvements effectually avoid these difficulties, and consist in exposing the mass of pulverized ore, mixed with carbonaceous matter, to

the combined action of a gentle flame or heat; and currents of heated

air passing through the mass, which in their passage not only agitate the mass, to aid the mechanical liberation of the gases evolved, but aid in evolving the gases from the oxide and carbon, which in their nascent state combine and revive the metallic particles. “The mass is then subjected to the combined action of a more intense flame, and to highly heated currents of carburetted hydrogen gas, that pass through the mass and take up the remaining oxygen of the ore, and revive the metallic particles; and then the mass passes to the puddling process, where it is subjected to a still more intense heat, and to the action

of jets of highly heated atmospheric air, to consume the carbonaceous:

matter, and free it from other impurities. For the application of my improved process, I have made important modifications in the well known reverberatory furnace, which for this purpose is made of much greater length than those heretofore used.” Letters patent have also been granted for an improvement in furnaces for reducing iron ores, whose objects are to facilitate and economize fuel. Two stacks are placed side by side, with a blast for each, which, as occasion requires, may be diverted in such a manner that nearly the whole blast may be directed to one of the stacks, while the charge in the other preserves sufficient heat for its stage of the process. It is believed that extracts from the patent are unnecessary. Steel—Two patents have been granted this year for improvements in the manufacture of steel. The process resorted to by the first patentee is simple, and the rationale obvious. He obtains iron of the quality of pig iron directly from the ore, in the ordinary way, and preserves it in a melted state. The liquid iron has a larger proportion of carbon than is contained in steel. Knowing by experiment the relative proportion of the iron and carbon in the melted mass, he dilutes it, if such a term may be used, with pure malleable iron, which melts with the mass, until the iron and carbon acquire the relative proportions which are found in steel. The mass is then drawn off and allowed to cool. The product of this process will doubtless possess in combination all the elements of steel; but whether all parts of the mass will be equally impregnated with carbon, or whether a portion of it will be steel and other portions pig-iron variously carbonized, are questions which ironmasters and others will not fail to ask, and the value of the alleged improvement will depend upon the answer. The foregoing invention was made in England, and first patented there. The particulars of the above process will be understood by the following extract from the patent: “The process now universally in use for making cast steel is to reduce

vapor. The deutoxide of nitrogen, as it escaped from the hole, seized on the oxygen of the air, and was changed to orange-yellow vapor. There was a faint smell of nitrous acid about the rock. Pieces of the India rubber cloth were found near the hole, thrown off but unburnt. It was, 'I presume, this yellow nitrous vapor which appeared as dust in the first explosion. The smoke lasted about one minute.

- he gun-cotton used in these trials was perfectly dry, and well carded after its preparation. "It was made from cotton carded by a machine, and was prepared by myself, by the principle of the process discovered by Mr. A. A. Hayes, of the Roxbury laboratory.

In a slight notice in your paper, a few days ago, of some successful trials made in Lowell with gun-cotton, you have inadvertently awarded to myself the honor of the discovery of the mode of its formation. I cannot claim this desirable distinction. This belongs exclusively to Mr. Hayes, who was the first in Boston, or its vicinity, not only to discover, but, with that courtesy so often united to true science, the first to publish his results. He immediately informed me of his success by a letter dated Thursday morning, November 19th, which I received the next day at noon. It enclosed samples of his gun-cotton, which, with his letter, were forthwith shown to several persons here. In the .. of the 19th November, Mr. Hayes's gun-cotton and processes were exhibited by his friend Tesche. macher at a meeting in Boston of several gentlemen devoted to science, or interested in all that pertains to its application. It was at this meeting that the first gun-cotton, prepared either in Boston or its vicinity, was exhibited, and its mode of preparation detailed in a written communication. Minutes were copied from this by at least one person present. The day following there appeared in an evening paper, in Boston, accounts of success in forming eaplosive cotton; but there was no allusion to the light by whose borrowed rays had been obtained even partial success. Had the process of Mr. Hayes been followed as implicitly as it had been freely disclosed, the preparation would have equalled that which had already been exploded in several public places in Boston on Friday morning, November 20th, and which was prepared by Mr. Hayes. On Saturday, the 21st ultimo, appeared a letter from Mr. H. in the Boston Daily Advertiser, which, with plentiful samples of gun-cotton, had been sent to its editor on the preceding Thursday, several hours before the assembling of the meeting to which I have referred. n The preparation of eaplosive and of gun cotton has been discovered by several persons in Europe and in America, since Schönbein first made the world acquainted with this singularly wonderful compound. These all may be rediscoveries of his mode, for of that we as yet know nothing; but they are not the less original, nor less honorable, nor less dear to the scientific character of their authors. I am happy to embrace this opportunity to state the true claims of my friend Hayes. I have had other trials made with gun-cotton by experienced riflemen. They show that its power is from four to eight times that of the best rifle powder. These experiments are as yet unfinished, and will form the subject of a future communication. With regard, your obedient servant,

SAMUEL L. DANA.

Lowell, December 7, 1846.

... Alleviation of pain during surgical operations.—The discovery patented under this caption presented itself as one of extensive moment, and the patentability of the subject was predicated upon grounds similar to the last named discovery, viz: gun-cotton. The process is one of exceeding simplicity, being merely the inhalation of the vapor of sulphuric ether, to prepare the patient for painful surgical operations. It has been known for many years that the vapor of ether, when freely inspired, would intoxicate to the same extent as alcohol taken into the stomach; and that while the effects of the latter were lasting and hazardous when carried to stupefaction, the former was temporary in its power over the system, and usually left no uncomfortable feelings after the first effects had subsided. It has also long been the practice of surgeons to administer opiates previous to severe operations, the materials employed varying according to circumstances—in some instances, opium; in others, alcohol in some form; these two being most generally adopted. It is possible that in such cases some rash hand may have carried the effects of these drugs even to the entire subversion of sense, but such has never been admissible or reasonable practice; the dose given, on the contrary, operating only to the extent of a palliative. The fact has stood forth upon the pages of science for many years, that the inhalation of sulphuric ether was productive of temporary narcotic-stimulant effects, and it was also known that the excessive use of this stimulant had, on some few occasions, been followed by alarming symptoms. But, notwithstanding this familiar record in the possession of every surgeon, it was never attempted to substitute this for the pallia...tives in common use previous to surgical operations, nor was it known to what extent it rendered the system insensible to pain. It is doubtful if the narcotic effects of either alcohol or opium could render a person insensible to the pain of a surgical operation such as the amputation of a leg, unless the exhibition of the dose were such as absolutely to endanger life. In view of the above and other considerations, a patent has been granted for this discovery. Much has been said for and against the introduction of this discovery, but the weight of authentic statements is decidedly in its favor. The testimony of individuals, or bodies of men, is rarely necessary prior to the grant of a patent, and but seldom regarded— the question of novelty being that usually entertained; but as this patent has been granted upon proof of novelty, it may be well to cite a few remarks from the high authority of Dr. J. C. Warren, professor of anatomy in the Massachusetts Medical College. After detailing a number of sur§. operations, he closes a communication in the Boston Medical and urgical Journal of December 9, 1846, as follows: - “Ist. The breathing of the ethereal vapor appears to operate directly on the cerebral system, and the consequent insensibility is proportionate to the degree of cerebral affection. “2d. Muscular power was for the time suspended in some cases; in others its loss was partial, and in one instance was scarcely sensible. The great relaxation produced by a full dose of the application leads to the hope that it may be employed with advantage in cases of spasmodic affection, both by the surgeon and by the physician. “3d. The respiration is sometimes stertorous, like that of apoplexy. “4th. The action of the heart is remarkably accelerated in some cases, but not in all. “All these changes soon pass off without leaving any distinct traces be